Detection of veterinary drug residue in an animal-derived food sample is of great significance for food safety. Sample preparation is the first step during the process of drug residue detection. The aim of sample preparation is to separate out the composition to be analyzed from a given sample, so that the composition can be analyzed. The main purpose of sample preparation is to release the drug residue from the sample, remove the interfering impurities, convert the drug residue to a state that can be analyzed and a concentration that is suitable for analysis, and/or make the drug residue dissolvable in a suitable solvent. The success of sample preparation directly affects the accuracy of drug residue detection.
Sample preparation requires use of devices. At present, there is no device that is specifically designed for detection of drug residue. Instead, many separate apparatuses such as water bath, vortex mixer, homogenizer, and centrifuge have to be used.
However, there are shortcomings for use of the apparatuses:
1) The number of samples that can be processed by a vortex mixer at a given time is very low. Furthermore, because no built-in structures exist for holding the centrifuge tube in the vortex mixer, the operator has to hold the tube(s) against the vortex head for an extended time, leading to hand numbness.
2) There are safety issues associated with use of homogenizers. It is also inconvenient to clean the blade and heads of the homogenizer.
3) Because the apparatuses are not integrated, the efficiency of the operation is very low.